1. Field of the Invention
The present invention relates to an optical fiber cable connector assembly, and particularly to a pre-assembled FC type optical fiber cable connector assembly which facilitates storage and shipping, and when received by the ultimate consumer, is ready for installation on an optical fiber cable.
2. Description of the Prior Art
In the conventional FC type optical fiber cable connector, the different components of the connector assembly are separately stored in inventory before they are combined for installation on an optical fiber cable. These different separate components are transferred to a workstation or to a customer where the optical fiber cable is ready for installation of these components on the optical cable by a technician through use of special tools to assemble these components to the optical fiber cable. From the viewpoint of handling and shipping, these separately inventoried components occupy more storage space and require more time during the manufacturing process, resulting in increased costs and inefficiency.
Referring to FIGS. 1, 2 and 3, or as disclosed in U.S. Pat. No. 4,747,659, the conventional FC optical fiber cable connector comprises a first tubular housing 1' and a second housing 2', retained assembled by the threaded interengagement of an internal threaded portion 11' of the first housing 1' and an external threaded portion 21' of the second housing 2'. A coupling nut 3' slidably moves along an outer surface of a rear portion of the first housing 1' within the limits imposed by external and radially outward projecting flanges 12' and 22' of the first housing 1' and the second housing 2', respectively, and an internal and radially inwardly projecting flange 31' of the coupling nut 3'. Associated with a coil spring 5', a plunger or alignment ferrule 4' is removably positioned within an inner space of the assembly of these two housings. A sleeve or boot 6' accompanying a crimping ferrule 7' is connected to a rear portion of the second housing 2'. With reference to FIGS. 2 and 3, when an optical fiber cable 8' is ready for assembly with the connector, a front end portion of the cable jacket 81' is removed to expose multiple strands of "Kevlar" or strength members 82'. These are sandwiched and fastened between the rear portion of the second housing 2' and the crimping ferrule 7'. A flexible buffer 83' within the strength member 82' centers a fiber 84' which extends forward into the second housing 2' and enters the alignment ferrule 4'.
For the sake of stabilization, the buffer 83' must be adhered to the inner surface of the alignment ferrule 4', and a quantity of adhesive, for example epoxy, may therefore be applied thereto. It is noted that if the components have been assembled as shown in FIG. 2 before combination with the optical fiber cable, it is not easy for a technician to inject the adhesive into the inner portion of the alignment ferrule 4' for fastening the buffer 83' without the likelihood of contamination of the inner portion of the second housing 2' due to the fact that the rear end portion 41' of the alignment ferrule 4' is deeply embedded within the second housing 2' and end 41' of the alignment ferrule 4' is far from the end opening 23' of the second housing 2'.
In other words, in that condition, the adhesive may invade the interior space between the second housing 2' and the alignment ferrule 4', even sticking to the coil spring 5' and jeopardizing its resilient bumper function. Accordingly, the components of the prior art fiber optical connector are held in inventory separately until the optical fiber is available to be combined therein. That is, the steps include passing the front end of the fiber cable 8' through the boot 6', the crimping ferrule 7', and the second housing 2' individually and sequentially, and directly faces into and moves close to the alignment ferrule 4', so the application of adhesive between the alignment ferrule 4' amd the fiber buffer 83' is under proper control without the risk of contamination to the second housing 2'. Consecutively, the second hosuing 2', which has surrounded the fiber cable, is moved toward the alignment ferrule 4' and connects with the first housing 1' by the corresponding threaded portions, accompanied by the coupling nut 3' surrounding the first housing 1' and the second housing 2' so that the internal radially inward extending flange 31' is positioned between the external radially outward extending flange 12' of the first housing 1' and the external radially outward extending flange 22' of the second housing 2'. Lastly, the crimping ferrule 7' presses the strength members 82' on the end portion of the second housing 2' and are covered by the boot 6'. As discussed above, obviously, this conventional FC type optical fiber connector has the disadvantage that it cannot be a semi-finished or a pre-assembled type product for the customer who is the manufacturer of an optical fiber cable and who intends to attach the connector to one end of the optical fiber cable for finalizing a completed product assembly. The disadvantage will result in excessive handling and inventory problems for the manufacturer.
By contrast, as shown in FIGS. 4 and 5, or in U.S. Pat. Nos. 4,634,214; 4,834,487; 4,911,518; and 5,033,808, an ST type optical fiber connector may be pre-assembled and ready for the further combination with the optical fiber cable under the condition that the epoxy adhesive can be controlled to not contaminate or spoil the outside portion of the alignment ferrule 1" because the alignment ferrule 1" extends outside to facilitate approach when the fiber cable is applied to this semifinished product. The obvious difference between an FC type connector and an ST connector is that the former is a two-housing enclosure and the latter is a one-housing enclosure. So, compared with an FC type connector, the obvious disadvantage of an ST type connector is that the strength members 2" are disposed onto the alignment ferrule 1" directly and sandwiched between the crimping ferrule 3" for combination of the cable and the connector, so that during mating with another corresponding connector, any occurring force acting on the ST connector will easily transfer detrimentally to the optical fiber due to its simple structure. It can be understood that in a poor environment, any slight vibration or movement of the optical fiber will result in undesired misinformation transfer or a communication interruption.
For the purpose of overcoming the respective flaws of these two different type connectors, it is an object of the present invention to provide an FC type connector which provides the respective advantages of these two type prior art connectors but without their respective disadvantages. Another object of the present invention is to provide an FC type connector that may be pre-assembled as a semi-finished product for convenience of stroage and shipping, like an ST connector, without the risk of contamination in further assembling with the optical fiber cable and which also keeps the better bumper effect during mating like an FC connector for maintaining true and reliable communication.